Commonly assigned U.S. Pat. No. 5,126,715 of A. J. Yerman and W. A. Roshen, issued Jun. 30, 1992 and incorporated by reference herein, describes a low-profile, multi-pole, conductive film transformer. The transformer of U.S. Pat. No. 5,126,715 includes a continuous, serpentine primary winding that is configured and z-folded to form a multi-pole, multi-layer winding having separate secondary winding layers interleaved therewith. Conductive connecting strips are used to electrically connect the separate secondary winding layers together.
The conductive film transformer of U.S. Pat. No. 5,126,715 is limited to single-turn secondary windings. In addition, the single-turn secondary winding has rather complicated winding terminations, which limits its application and increases the losses. However, it is desirable for many applications to employ a multi-turn secondary winding in order to lower the magnetic flux density in the core and furthermore to reduce the height of the device. To be practicable, such a multi-turn winding configuration should have relatively simple winding terminations and connections and should have relatively low winding losses.